Here are mine:
* “What on earth was my subconsciousness thinking!?” - Haruhi
* “However, as always, this girl was thinking up all sorts of nonsensical stuff. I can't help but wonder if there's a white hole inside her head, since her common sense seems to come from a different universe altogether.” ~ Kyon
* “A localized, non-corrosive amalgamation of asynchronous space is independently occurring in restricted condition mode.” ~ Yuki (?)

* “Even if you're speaking with phrases that make it seem like you just pulled words out of a dictionary and lined them up after they caught your eye, I, having no dictionary, am helpless.” ~ Haruhi
“What're you doing here then?” ~ Kyon
“What else would I be here for? To illegally enter the premises, of course.” ~ Haruhi
* “Don't openly declare your criminal intentions like that, there's a limit to being shameless!” ~ Kyon
"What would be nice? Hotpot? Sukiyaki? Crab is a no-no. I can't take it. Picking the flesh out of the shell drives me nuts. Why can't crabs make their shells edible? How come they didn't do anything about that during the course of evolution, might I ask?" ~ Haruhi (?)
* "That's exactly why they evolved shells! They don't undergo natural selection in the depths of the sea just for the sake of your stomach!" ~Kyon (?)

"Personally, I'd say... the best one on the class is her. Ryoko Asakura. She's gotta be in the top three for our year." ~ Taniguchi
"An AA+. She's definitely a nice person, too." ~ Taniguchi

"I've never seen Suzumiya talk that long before. What did you say to her? It's the end of the world." ~ Taniguchi
"Kyon's always liked weird girls." ~ Kunikida
"Onegai. (Pretty please.)" ~ Ryoko

*"You know... humans have a saying, "It's better to regret something you did than to regret something you didn't do."" ~ Ryoko
*"Wouldn't you think that change, any change at all, would be best for now?" ~ Ryoko
"In that case, it should be okay for me to use my own judgment to assert changes, right?" ~ Ryoko
"What is she trying to say? Is this a prank? Is Taniguchi or someone hiding in the broom closet?" ~ Kyon

A normal high schooler who accidentally pressed a button that activated a time bomb, and is now being forced to carry that bomb around like a moron - that's me. - Kyon

As this Oolong tea was made by the gods, it must be as sweet as all the heavenly elixirs combined. - Kyon

I cannot completely convey this in words, and there may be discrepancies in the transmission of data. -Yuki

I'll give you a smaller sentence, go run ten laps around the school field naked and shout 'I'm being chased by little green men!' - Haruhi

Now let me set the record straight, I am an absolutely normal heterosexual male. My preference for "the same team" weighs less than that of a humming bird, in other words, it's non-existent. Whether subconsciously or unconsciously, my preference has been "straight". See? Aren't I right? My body would go hot just thinking about Asahina-san. If Koizumi had called me saying such stuff, I would've hung up already. By the way, I'm not bisexual either. Do I make myself clear? - Kyon

Classified information. - Yuki <~~Yes, she said it also.

And Kyon also appears to be more retarded than normal as he did not realise spring has already arrived.
- Haruhi

"Kyon, a duel is a duel from the very moment the word is said!" ~Haruhi, The Day of Sagittarius III (English dub)

"Are you forgetting that I am the sacred and divine figure head of the SOS Brigade? I'm your leader, dummy! I will never give up this position except to the person I feel is the chosen one." ~Haruhi, The Day of Sagittarius III (English Dub)

"So you mean you're gonna stay here even after you graduate?!" ~Kyon, The Day of Sagittarius III (English dub)

"At least we've got Nagato on our side. [Nagato waves mouse in the air] I take it back; we're dead." ~Kyon,The Day of Sagittarius III

"Miss Asahina, the gaming novice, and Haruhi, the charging idiot are completely useless." ~Kyon, The Day of Sagittarius III (English dub)

"The enemy is using the V-formation to try and lure us into their firing range. I think we should counter with a defensive strategy." ~Itsuki, The Day of Sagittarius III (English dub)

"Anyone accept defeat will be punished by running 10 laps around the entire school! NAKED! And you'll have to yell 'Green martians are chasing me' for the whole 10 laps!" ~Haruhi, The Day of Sagittarius III

"Uuuuuummmmm, Miss Nagato, yeah, hi. What exactly are you doing right now?" ~Kyon, The Day of Sagittarius III

"We managed to destroy 2 of the enemy fleets, and the others are looking a bit confused. Thanks to Miss Nagato's squadron, it looks the tides of war of turned in our favor." ~Itsuki, The Day of Sagittarius III

"I don't know what just happened, but great job guys! All ships, open fire! Go out there and destroy the enemy with all the burning flames of hell!" ~Haruhi, The Day of Sagittarius III (English dub)

The world sure isn't worth much these days."-Kyon; The Boredom of Haruhi Suzumiya (Ep. 4),
"Hey, Hey! You can't rent Yuki without my permission! Understood? She's the SOS Brigade's indispensible silent character! I saw her first!" -Haruhi, Episode 11 ,Shamisen: "There is no need to consider his words. Why don't you just take control of his mind? From my observations you possess the ability to do just that."Yuki: "That was ventriloquism."-Episode 1
MORE!!

Even if you're speaking with phrases that make it seem like you just pulled words out of a dictionary and lined them up after they caught your eye, I, having no dictionary, am helpless.”
i like this one>.<

"Then I'll tell everyone you geeks ganged up on her and <bleep>ed her!" ~Haruhi

idk why i thought this was funny.

I agree! I fell over laughing when Haruhi took the Computer Club Chief's Hand and put it on Mikuru's 'bust', but it was even funnier (and even fell over a second time laughing) when that line was uttered! LOL! That whole situation in the episode was funny as hell!